1. Field of the Invention
This invention relates, in general, to a locking mechanism for releasingly locking a shaft to a tool attachment cavity with the more specific implementation of use of releasingly locking a socket onto socket wrench shaft drive.
2. Background of the Invention
The desirability of some type of locking drive for a socket wrench system has long been recognized as a means to prevent the system components from uncoupling. For example, U.S. Pat. No. 4,480,511 of M. F. Nickipuck titled "Locking Socket Wrench Drive Device" describes a socket wrench extension having drive end that locks onto a socket, and U.S. Pat. No. 4,502,365 of K. M. Hacker titled "Socket Wrench Extension" also describes an extension with a releasing locking device on the drive. U.S. Pat. No. 4,781,085 titled "Locking Socket Wrench Extension" of current co-inventor L. Fox III describes another such device. U.S. Pat. No. 4,962,682 titled "Wrench Extension and Socket Coupler" to Rose et al. describes a push button locking device for a wrench extension.
The desirability of a locking ratchet drive is also seen in the prior art. U.S. Pat. No. 4,399,722 of V. Sardo titled "Socket Wrench Including Quick Release Adaptor" describes a ratchet drive including a mechanism for locking a socket to the drive head.
Due to the added complexity and expense of these devices, most ratchet drives sold do not contain a locking feature and the conventional locking devices suffer from one or more shortcomings. They are overly complex, expensive, difficult to assemble, difficult to use, or jam or do not work when subjected to a dirty environment.
In this regard, it is also desirable that any locking mechanism components do not protrude beyond the outer diameter of the shaft.
Therefore, there has been a need for a an improved locking mechanism for a shaft drive such that its addition to the drive does not noticeably alter the performance and handling of the ratchet driver.